Replaces Babel with SWC for Next.js core client-side files.
## Bug
- [ ] Related issues linked using `fixes #number`
- [ ] Integration tests added
- [ ] Errors have helpful link attached, see `contributing.md`
## Feature
- [ ] Implements an existing feature request or RFC. Make sure the feature request has been accepted for implementation before opening a PR.
- [ ] Related issues linked using `fixes #number`
- [ ] Integration tests added
- [ ] Documentation added
- [ ] Telemetry added. In case of a feature if it's used or not.
- [ ] Errors have helpful link attached, see `contributing.md`
## Documentation / Examples
- [ ] Make sure the linting passes
This will ensure `next/script` follows the same naming convention as `next/image`. For example:
```js
import Image, { ImageProps } from 'next/image'
import Script, { ScriptProps } from 'next/script'
```
Fixes#26290
This fixes the React warning: `Warning: Each child in a list should have a unique "key" prop.` that is thrown when using the `Script` components with the `beforeInteractive` strategy.
Fixes: #26618
* Remove deprecated features
In the next major version we'll want to merge this PR that removes some of the long-time deprecated features, it'll have a positive effect on bundle size.
* Update tests
* Update tests
* Change unsized to layout=fill in test
* Update sizes
* Update rotation test
* Update size limit test
* Update test
* Update test
* Update test
## Bug
- [ ] Related issues linked using `fixes #number`
- [ ] Integration tests added
## Feature
- [ ] Implements an existing feature request or RFC. Make sure the feature request has been accepted for implementation before opening a PR.
- [ ] Related issues linked using `fixes #number`
- [ ] Integration tests added
- [ ] Documentation added
- [ ] Telemetry added. In case of a feature if it's used or not.
## Documentation / Examples
- [ ] Make sure the linting passes
As discussed with @csswizardry. This is a temporary option in case you know the preloads are not needed. It will likely be a default once the ScriptLoader work from @janicklas-ralph has been proven in partner apps and landed.
```js
// pages/index.js
export const config = {
unstable_JsPreload: false
}
```
There's currently two bugs with the font optimization, but we'd really like to ship a stable version.
To unblock the stable release, we're **temporarily** reflagging this. It'll be unflagged on canary again!
This PR removes the modern mode experiment because:
- It does not yield meaningful bundle size wins when compared to other initiatives we've taken
- It's not compatible with webpack 5 (which we're upgrading to)
- It's currently broken and causes most apps to malfunction
- There's no champion currently owning the experiment
We can re-introduce this in the future when we'd like to make it a default for all Next.js apps.
Note: **Next.js still supports Differential Loading (`nomodule`) and does it by default.** This PR strictly removes the experimental modern _syntax_, and does not disable our existing modern/legacy polyfilling.
---
Fixes#19200Fixes#18960Fixes#14707Fixes#14465
The rule [total-functions/no-unsafe-readonly-mutable-assignment](https://github.com/danielnixon/eslint-plugin-total-functions#total-functionsno-unsafe-readonly-mutable-assignment) triggers with this error message:
> Assigning a readonly type to a mutable type can lead to unexpected mutation in the readonly value
when invoking
```
NextScript.getInlineScriptSource(this.props)
```
inside a `_document.tsx`'s render function.
due to `this.props` having the type:
```
props: Readonly<P> & Readonly<{ children?: ReactNode }>
```
in `@types/react`
On the other hand, this is a small, low-priority change (IMO), so an alternative work around is just to disable the lint rule for that line of course.
Lint, tests, and build passes.
Lint error was discovered using typescript@next, version `4.1.0-dev.20200921` and eslint-plugin-total-functions version `4.1.0`, but I tested the change to nextjs using typescript version `3.8.3`.
Serverside Dynamically loaded CSS module file insertion adds css-files as usual static files with special data-n-p tag, that is used in page transition logic. That files get removed on page transition cause they are not explicitly required in scope of page.
Mini-css-extract-plugin adds style tags at chunk insertion without any tags and leave them be, no matter how many page transitions were made.
I removed data-n-p tag from dynamically loaded css module files and added new data-n-d tag for it.
Fixes#16950
This adds the initial changes outlined in the [i18n routing RFC](https://github.com/vercel/next.js/discussions/17078). This currently treats the locale prefix on routes similar to how the basePath is treated in that the config doesn't require any changes to your pages directory and is automatically stripped/added based on the detected locale that should be used.
Currently redirecting occurs on the `/` route if a locale is detected regardless of if an optional catch-all route would match the `/` route or not we may want to investigate whether we want to disable this redirection automatically if an `/index.js` file isn't present at root of the pages directory.
TODO:
- [x] ensure locale detection/populating works in serverless mode correctly
- [x] add tests for locale handling in different modes, fallback/getStaticProps/getServerSideProps
To be continued in fall-up PRs
- [ ] add tests for revalidate, auto-export, basePath + i18n
- [ ] add mapping of domains with locales
- [ ] investigate detecting locale against non-index routes and populating the locale in a cookie
x-ref: https://github.com/vercel/next.js/issues/17110
Removes `next-head-count`, improving support for 3rd party libraries that insert or append new elements to `<head>`.
---
This is more or less what a solution with a `data-` attribute would look like, except that instead of directly searching for elements with that attribute, we serialize the elements expected in `<head>` and then find them/assume ownership of them during initialization (in a manner similar to React's reconciliation) based on their properties.
There are two main assumptions here:
1. Content is served with compression, so duplicate serialization of e.g. inline script or style tags doesn't have a meaningful impact. Storing a hash would be a potential optimization.
2. 3rd party libraries primarily only insert new, unique elements to head. Libraries trying to actively manage elements that overlap with those that Next.js claims ownership of will still be unsupported.
The reason for this roundabout approach is that I'd really like to avoid `data-` if possible, for maximum compatibility. Implicitly adding an attribute could be a breaking change for some class of tools or crawlers and makes it otherwise impossible to insert raw HTML into `<head>`. Adding an unexpected attribute is why the original `class="next-head"` approach was problematic in the first place!
That said, while I don't expect this to be more problematic than `next-head-count` (anything that would break in this new model also should have broken in the old model), if that does end up being the case, it might make sense to just bite the bullet.
Fixes#11012Closes#16707
---
cc @Timer @timneutkens
This pull request replaces our client-side style transitions with `<style>` tags over async `<link rel=stylesheet>` tags. This should fix some edge cases users see with Chrome accidentally causing a FOUC.
This also removes the need to perform an async operation before starting the render, which should remove any perceivable navigation delay.
---
Fixes#16289
To prevent FOUC, discussed in #10557 i need to store information about css file dependencies for chunk. Right now current implementation just throws away everything but js.
Can there be more than one css file in chunk? If no - code will be simplified.
closes#10557
This pull request adds a test case for the reproduction provided in #12445. This bug is specifically caused when loading the next page before navigation has actually occurred.
---
Fixes#12445
Fixes: #13512
Defined and exported type for `metric` used in [reportWebVitals](https://nextjs.org/docs/advanced-features/measuring-performance)
```
export function reportWebVitals(metric) {
if (metric.label === 'custom') {
console.log(metric) // The metric object ({ id, name, startTime, value, label }) is logged to the console
}
}
```
One can now do
```
import { NextWebVitalsMetric } from 'next/app'
export function reportWebVitals(metric: NextWebVitalsMetric ) {
if (metric.label === 'custom') {
console.log(metric) // The metric object ({ id, name, startTime, value, label }) is logged to the console
}
}
```
Updates the way filenames are generated for browser compilation.
Notably:
- All entry bundles now have hashes in production, this includes pages (previously pages used a buildId in the path)
- The AmpFiles no longer depends on hardcoded bundle names, it uses the buildManifest instead (internals)
- All cases where we match the page name from the chunk/entrypoint name now use the same function `getRouteFromEntrypoint` (internals)
- In development we no longer include the "faked" `buildId` set to `development` for page files, instead we just use the `/_next/static/pages` path (was `/_next/static/development/pages`). This was changed as it caused unneeded complexity and makes generating the bundles easier (internals)
- Updated tons of tests to be more resilient to these changes by relying on the buildManifest instead of hardcoded paths (internals)
Follow up of these PRs:
https://github.com/vercel/next.js/pull/13759https://github.com/vercel/next.js/pull/13870https://github.com/vercel/next.js/pull/13937https://github.com/vercel/next.js/pull/14130https://github.com/vercel/next.js/pull/14176https://github.com/vercel/next.js/pull/14268Fixes#6303Fixes#12087Fixes#1948Fixes#4368Fixes#4255Fixes#2548
Webpack will randomly execute script order if its runtime is not prioritized before chunks execute.
This seems to be somehow triggered in #13870 because of slightly different script ordering.
This had actually broke CSS, which is why our tests are failing 50% of the time:
Without this PR:
However, it's still problematic to use `async` in development since we rely on script execution order. So, this PR disables `async` in development.
We're exploring `defer` in the future anyway (over `async`), which will be ordered, so I don't mind diverging between dev and prod in this way.
---
Fixes#13911
Initial work to use chunkhashes instead of buildid for the page files in production. This does not change the calculation of the filename itself initially.
